SUCCESSFUL TREATMENT OF DIGITAL OSTEITIS BY INTRAVENOUS REGIONAL PERFUSION OF CEFTIOFUR IN AN AFRICAN ELEPHANT (LOXODONTA AFRICANA).

A 41-yr-old African elephant ( Loxodonta africana ) presented with a swollen third digit of the left forelimb and a 2-cm hole in the pad. Corrective trimming, topical treatments, and an oral antibiotic resulted in apparent resolution; however, it reoccurred after 4 mo. Radiographs suggested bone lysis in the third phalanx, with the primary differential diagnosis being septic osteitis. Flushing with metronidazole solution and intravenous regional perfusion (IVRP) of the foot were commenced. A tourniquet was applied just above the carpus, an interdigital vein was identified by ultrasound, and into this vein 2 g (20 ml) of ceftiofur sodium solution, followed by 60 ml of heparinized saline, was administered. The foot was kept raised for 25 min and then the tourniquet was removed. IVRP was repeated every other day for 70 treatments over 6 mo. Healing occurred, which was confirmed radiographically. IVRP offers an excellent treatment modality in a well-trained elephant.

A RETROSPECTIVE STUDY OF THE LESIONS ASSOCIATED WITH IRON STORAGE DISEASE IN CAPTIVE EGYPTIAN FRUIT BATS (ROUSETTUS AEGYPTIACUS).

Egyptian fruit bats (Rousettus aegyptiacus) are one of many species within zoologic collections that frequently develop iron storage disease. The goals of this retrospective multi-institutional study were to determine the tissue distribution of iron storage in captive adult Egyptian fruit bats and the incidence of intercurrent neoplasia and infection, which may be directly or indirectly related to iron overload. Tissue sections from 83 adult Egyptian fruit bats were histologically evaluated by using tissue sections stained with hematoxylin and eosin, trichrome, and Prussian blue techniques. The liver and spleen consistently had the largest amount of iron, but significant amounts of iron were also detected in the pancreas, kidney, skeletal muscle, and lung. Hepatocellular carcinoma (HCC; 11) was the most common neoplasm, followed by cholangiocarcinoma (4). Extrahepatic neoplasms included bronchioloalveolar adenoma (3), pulmonary carcinosarcoma (1), oral sarcoma (1), renal adenocarcinoma (1), transitional cell carcinoma of the urinary bladder (1), mammary gland adenoma (1), and parathyroid adenoma (1). There were also metastatic neoplasms of undetermined primary origin that included three poorly differentiated carcinomas, a poorly differentiated sarcoma, and a neuroendocrine tumor. Bats with hemochromatosis were significantly more likely to have HCC than bats with hemosiderosis (P = 0.032). Cardiomyopathy was identified in 35/77 bats with evaluable heart tissue, but no direct association was found between cardiac damage and the amount of iron observed within the liver or heart. Hepatic abscesses occurred in multiple bats, although a significant association was not observed between hemochromatosis and bacterial infection. To the authors' knowledge, this is the first publication providing evidence of a positive correlation between hemochromatosis and HCC in any species other than humans.

Serum and hepatic vitamin A levels in captive and wild marine toads (Bufo marinus).

The captive breeding program for the endangered Puerto Rican crested toad (Peltophryne [Bufo] lemur) has been hampered by an undiagnosed condition called "Brown Skin Disease" (BSD). Toads develop widespread skin darkening, skin thickening and abnormal shedding and eventually succumb to a chronic loss of viability. This project evaluated the marine toad (Bufo marinus) as a model for the PRCT, examining vitamin A deficiency as a potential cause of BSD. Wild caught marine toads had significantly higher liver vitamin A concentrations (61.89 ± 63.49 µg/g) than captive born marine toads (0.58 ± 0.59 µg/g); P<0.001). A significant difference in serum vitamin A concentration was found between the captive and wild caught toads (P=0.013) and between the low vitamin A-fed and wild caught toads (P=0.004), when controlling for liver vitamin A concentrations. After captive toads were treated with topical and/or oral vitamin A, their hepatic vitamin A concentrations were similar to those of the wild toads, averaging 48.41 ± 37.03 µg/g. However, plasma vitamin A concentrations pre- and post-vitamin A supplementation did not differ statistically. We concluded that plasma vitamin A concentrations do not provide a linear indication of liver/body vitamin A status, and that both topical and oral supplementation with an oil-based vitamin A formulation can increase liver stores in amphibians. No evidence of BSD or other signs of deficiency were noted in the marine toads, although this feeding trial was relatively short (127 days). To date, clinical, pathological and research findings do not support vitamin A deficiency as a primary factor underlying BSD.

Anesthetic management of a white rhinoceros (Ceratotherium simum) undergoing an emergency exploratory celiotomy for colic.

OBSERVATIONS: A 26-year-old male white rhinoceros (Ceratotherium simum), weighing approximately 2000 kg was anesthetized for an exploratory celiotomy. Sedation was achieved with intramuscular butorphanol (0.04 mg kg(-1)) and detomidine (0.025 mg kg(-1)) and induction of anesthesia with intravenous glyceryl guaiacolate (50 g) and three intravenous boluses of ketamine (200 mg, each); the trachea was then intubated and anesthesia maintained with isoflurane in oxygen using a circle breathing system. Positioning in dorsal recumbency for the surgery and later in sternal recumbency for the recovery represented challenges that added to the prolonged anesthesia time and surgical approach to partially correct an impaction. The rhinoceros recovered uneventfully after 10.4 hours of recumbency. CONCLUSIONS: Anesthetic management for an exploratory celiotomy with a midline approach is possible in rhinoceroses, although planning and extensive staff support is necessary to adequately position the patient.

Iron storage disease (hemochromatosis) and hepcidin response to iron load in two species of pteropodid fruit bats relative to the common vampire bat.

Hepcidin is the key regulator of iron homeostasis in the body. Iron storage disease (hemochromatosis) is a frequent cause of liver disease and mortality in captive Egyptian fruit bats (Rousettus aegyptiacus), but reasons underlying this condition are unknown. Hereditary hemochromatosis in humans is due to deficiency of hepcidin or resistance to the action of hepcidin. Here, we investigated the role of hepcidin in iron metabolism in one species of pteropodid bat that is prone to iron storage disease [Egyptian fruit bat (with and without hemochromatosis)], one species of pteropodid bat where iron storage disease is rare [straw-colored fruit bat (Eidolon helvum)], and one species of bat with a natural diet very high in iron, in which iron storage disease is not reported [common vampire bat (Desmodus rotundus)]. Iron challenge via intramuscular injection of iron dextran resulted in significantly increased liver iron content and histologic iron scores in all three species, and increased plasma iron in Egyptian fruit bats and straw-colored fruit bats. Hepcidin mRNA expression increased in response to iron administration in healthy Egyptian fruit bats and common vampire bats, but not in straw-colored fruit bats or Egyptian fruit bats with hemochromatosis. Hepcidin gene expression significantly correlated with liver iron content in Egyptian fruit bats and common vampire bats, and with transferrin saturation and plasma ferritin concentration in Egyptian fruit bats. Induction of hepcidin gene expression in response to iron challenge is absent in straw-colored fruit bats and in Egyptian fruit bats with hemochromatosis and, relative to common vampire bats and healthy humans, is low in Egyptain fruit bats without hemochromatosis. Limited hepcidin response to iron challenge may contribute to the increased susceptibility of Egyptian fruit bats to iron storage disease.

Field implantation of intraperitoneal radiotransmitters in Eastern Wolf (Canis lycaon ) pups using inhalation anesthesia with sevoflurane.

In a study of wolf pup survival, intraperitoneal radio transmitters were surgically implanted in 53 (27 male and 26 female) 3.5- to 8-wk-old Eastern wolf (Canis lycaon) pups at den sites in Algonquin Provincial Park, Ontario, Canada, over two whelping seasons (2004 and 2005). Pups were manually removed from dens and initially injected with butorphanol at a dosage of 0.1 mg/kg for sedation and intra-operative analgesia. Anesthesia was induced and maintained with 3% sevoflurane in oxygen via a face mask. Meloxicam (0.3 mg/kg intramuscularly) was given to provide additional analgesia. All surgeries were completed without complications, and pups were readily accepted back into the packs. No postoperative complications were identified, but two pups from a single litter drowned as a result of being moved by the pack to a flooded den following the surgery. In five pups necropsied following natural deaths, transmitters were found lying free within the peritoneal cavity, and there was no evidence of infection at the surgical site or peritonitis. Inhalation anesthesia provided extremely rapid induction (1 min) and recovery (<3 min) and was completely controllable with no residual anesthetic effects. The equipment for inhalation anesthesia was readily portable in field packs, and it has considerable advantages over injectable drugs for small and very young animals such as wolf pups. The utility of the procedure is demonstrated by the minimal effect it had on subsequent pup survival, the rapid recovery of pups following surgery, and the lack of long-term complications as determined by necropsies of pups following natural deaths.

Short-term biological variation of clinical chemical values in Dumeril's monitors (Varanus dumerili).

Plasma biochemical values are routinely used in the medical management of ill reptiles, and for monitoring the health of clinically normal animals. Laboratory tests, including clinical biochemical values, are subject to biological and analytical variation, the magnitude of which determines the utility of population-based reference ranges for the detection of abnormal results in the individual animal. Nested analysis of variance of repeated measurements allows the variance to be broken into within-individual, between-individual, and analytical variation. When the within-individual variation is large and the interindividual variation is low, a sample may be accurately classified as normal or abnormal based on a population-based reference interval. However, if the intraindividual variation is low and the interindividual variation high, population-based reference intervals are of limited value as the ranges for an individual encompass only a part of the conventional reference interval. Between-lizard, within-lizard, and analytical components of variance were assessed by nested analysis of variance for 16 commonly measured plasma biochemical parameters in eight healthy adult Dumeril's monitors (Varanus dumerili). Albumin, cholesterol, phosphate, calcium, sodium, and total protein demonstrated levels of individuality suggesting that comparison of a single measurement to a conventional population-based reference range may be too insensitive to detect small but significant alterations in the value for that animal. Only for potassium and AST did the index of individuality suggest that the use of reference values may be warranted. Uric acid, globulin, glucose, and amylase fell in a gray zone, where population-based ranges should be used with caution. The critical difference indicates the difference between two consecutive analytical results that may be safely ascribed to natural variation. In the present study critical difference varied from 7 and 11%, respectively, for sodium and chloride to 75 and 125% for uric acid and AST.

Varanid herpesvirus 1: a novel herpesvirus associated with proliferative stomatitis in green tree monitors (Varanus prasinus).

Stomatitis is a common problem in lizards, and the etiologies of stomatitis in lizards are not well understood. Four green tree monitor lizards (Varanus prasinus) from two different collections were evaluated because of proliferative stomatitis. Degenerate PCR primers targeting a conserved region of herpesvirus DNA-dependent DNA polymerase were used to amplify and sequence a product from gingival tissue of three of four lizards (cases 1, 3, and 4). DNA in situ hybridization of tissues from three lizards was positive for herpesvirus in the oral mucosa of all three lizards tested (cases 1-3) and the brain of two lizards (cases 1 and 3). Comparative sequence analysis suggests that this virus is a novel member of the subfamily alpha-herpesvirinae, and is here termed varanid herpesvirus 1.

Minimum alveolar concentration of isoflurane in mechanically ventilated Dumeril monitors.

OBJECTIVE: To determine minimum alveolar concentration (MAC) of isoflurane in mechanically ventilated Dumeril monitors (Varanus dumerili). DESIGN: Prospective study. ANIMALS: 10 healthy adult Dumeril monitors. PROCEDURE: Anesthesia was induced with isoflurane in oxygen delivered through a face mask. Monitors were endotracheally intubated, and end-tidal and inspired isoflurane concentrations were continuously measured. After equilibration at an end-tidal-to-inspired isoflurane concentration ratio of >0.9 for 20 minutes, an electrical stimulus (50 Hz, 50 V) was delivered to the ventral aspect of the tail for up to 1 minute and the monitor was observed for purposeful movement. End-tidal isoflurane concentration was then decreased by 10%, and equilibration and stimulation were repeated. The MAC was calculated as the mean of the lowest end-tidal isoflurane concentration that prevented positive response and the highest concentration that allowed response. A blood sample for blood gas analysis was collected from the tail vein at the beginning and end of the anesthetic period. RESULTS: Mean +/- SD MAC of isoflurane was 1.54 +/- 0.17%. Mean heart rates at the upper and lower MAC values were 32.4 +/- 3 beats/min and 34 +/- 4.5 beats/min, respectively. During the experiment, PaCo2 decreased significantly from 43.1 mm Hg to 279 mm Hg and blood pH and HCO3 concentration increased significantly from 7.33 to 7.64 and from 25.3 to 32.9 mmol/L, respectively. CONCLUSIONS AND CLINICAL RELEVANCE: The MAC of isoflurane in Dumeril monitors was similar to that reported in mammals but lower than values reported in other reptiles. This difference may be reflective of the more advanced cardiovascular physiologic features of monitor lizards.

Anesthetic potency of sevoflurane with and without nitrous oxide in mechanically ventilated Dumeril monitors.

OBJECTIVE: To determine the minimum alveolar concentration (MAC) of sevoflurane and assess the sevoflurane-sparing effect of coadministration of nitrous oxide in mechanically ventilated Dumeril monitors (Varanus dumerili). DESIGN: Prospective crossover study. ANIMALS: 10 healthy adult Dumeril monitors. PROCEDURE: Anesthesia was induced with sevoflurane in 100% oxygen or sevoflurane in 66% nitrous oxide (N2O) with 34% oxygen, delivered through a face mask. Monitors were endotracheally intubated, and end-tidal and inspired isoflurane concentrations were measured continuously; MAC was determined by use of a standard bracketing technique. An electrical stimulus (50 Hz, 50 V) was delivered to the ventral aspect of the tail as the supramaximal stimulus. A blood sample for blood gas analyses was collected from the ventral coccygeal vessels at the beginning and end of the anesthetic period. An interval of at least 7 days was allowed to elapse between treatments. RESULTS: The MAC +/- SDs of sevoflurane in oxygen and with N2O were 2.51 +/- 0.46% and 1.83 +/- 0.33%, respectively. There was a significant difference between the 2 treatments, and the mean MAC-reducing effect of N2O was 26.4 +/- 11.4%. Assuming simple linear additivity of sevoflurane and N2O, the MAC for N2O was estimated to be 244%. No significant differences in blood gas values--with the predictable exception of oxygen pressure--were detected between the 2 groups. CONCLUSIONS AND CLINICAL RELEVANCE: The MAC of sevoflurane in Dumeril monitors is similar to that reported for other species. The addition of N2O significantly decreased the MAC of sevoflurane in this species.

Fatal cutaneous mycosis in tentacled snakes (Erpeton tentaculatum) caused by the Chrysosporium anamorph of Nannizziopsis vriesii.

The fungus Chrysosporium anamorph of Nannizziopsis vriesii was identified as the cause of fatal, multifocal, heterophilic dermatitis in four freshwater aquatic captive-bred tentacled snakes (Erpeton tentaculatum). Pale, 1- to 4-mm focal lesions involving individual scales, occurred primarily on the head and dorsum. Histology showed multifocal coagulation necrosis of the epidermis, with marked heterophilic infiltration without involvement of the underlying dermis. Septate, irregularly branched hyphae, and clusters of 4- to 8- by 2- to 3-microm rod-shaped cells (arthroconidia) were present within the lesions and in a superficial crust. Failure to maintain an acidic environment was likely a predisposing factor in the development of these lesions.

Inhalation anesthesia in Dumeril's monitor (Varanus dumerili) with isoflurane, sevoflurane, and nitrous oxide: effects of inspired gases on induction and recovery.

Induction and recovery from inhalation anesthesia of Dumeril's monitors (Varanus dumerili) using isoflurane, sevoflurane, and nitrous oxide (N2O) were characterized using a randomized crossover design. Mean times to induction for isoflurane in 100% oxygen (O2), sevoflurane in 100% O2, sevoflurane in 21% O2:79% nitrogen (N2; room air), and sevoflurane in 66% N2O:34% O2 were 13.00 +/- 4.55, 11.20 +/- 3.77, 10.40 +/- 2.50, and 9.40 +/- 2.80 min, respectively, at 26 degrees C (n = 10). Mask induction with sevoflurane was significantly faster than with isoflurane. There was no significant difference between the induction time for sevoflurane in O2 or in room air, but sevoflurane combined with N2O resulted in significantly faster inductions than were obtained with sevoflurane in 100% O2. All treatments resulted in a significantly higher respiratory rate than in undisturbed animals. There were no significant differences in respiratory rate among lizards receiving O2, isoflurane in 100% O2, sevoflurane in room air, and sevoflurane combined with N2O, but animals receiving sevoflurane in O2 had a lower respiratory rate than those receiving pure O2. The sequence of complete muscle relaxation during induction was consistent and not significantly different among the four treatments: front limbs lost tone first, followed by the neck and the hind limbs; then the righting reflex was lost and finally tail tone. There were no significant differences in recovery times between isoflurane and sevoflurane or between sevoflurane in 100% O2 and sevoflurane combined with N2O. Similar recovery times were observed in animals recovering in 100 and 21% O2.

Measurement of free glucocorticoids: quantifying corticosteroid-binding globulin binding affinity and its variation within and among mammalian species.

Plasma glucocorticoids (GCs) are commonly used as measures of stress in wildlife. A great deal of evidence indicates that only free GC (GC not bound by the specific binding protein, corticosteroid-binding globulin, CBG) leaves the circulation and exerts biological effects on GC-sensitive tissues. Free hormone concentrations are difficult to measure directly, so researchers estimate free GC using two measures: the binding affinity and the binding capacity in plasma. We provide an inexpensive saturation binding method for calculating the binding affinity (equilibrium dissociation constant, K d) of CBG that can be run without specialized laboratory equipment. Given that other plasma proteins, such as albumin, also bind GCs, the method compensates for this non-specific binding. Separation of bound GC from free GC was achieved with dextran-coated charcoal. The method provides repeatable estimates (12% coefficient of variation in the red squirrel, Tamiasciurus hudsonicus), and there is little evidence of inter-individual variation in K d (range 2.0-7.3 nM for 16 Richardson's ground squirrels, Urocitellus richardsonii). The K d values of 28 mammalian species we assessed were mostly clustered around a median of 4 nM, but five species had values between 13 and 61 nM. This pattern may be distinct from birds, for which published values are more tightly distributed (1.5-5.1 nM). The charcoal separation method provides a reliable and robust method for measuring the K d in a wide range of species. It uses basic laboratory equipment to provide rapid results at very low cost. Given the importance of CBG in regulating the biological activity of GCs, this method is a useful tool for physiological ecologists.

West Nile virus infection in the eastern loggerhead shrike (Lanius ludovicianus migrans): pathology, epidemiology, and immunization.

An outbreak of West Nile virus (WNV) infection occurred at a captive breeding facility for the endangered eastern loggerhead shrike (Lanius ludovicianus migrans) in August 2002. Within 10 d, five birds died; two were found dead, and the others died shortly after showing neurologic signs. West Nile virus was detected in all organs examined using immunohistochemistry, and its viral genome was amplified from brain and kidney samples using reverse transcription-polymerase chain reaction. None of the remaining birds in the colony had antibodies against WNV, which suggests a mortality rate of 100%. After vaccination with a commercial equine WNV vaccine 31 of 37 (84%) of the birds had WNV neutralizing antibodies.

Surgical management of rectal prolapse in an Indian rhinoceros (Rhinoceros unicornis).

An acute rectal mucosal prolapse in a 26-yr-old Indian rhinoceros (Rhinoceros unicornis) was repaired surgically by mucosal resection. Two days postoperatively, suture line dehiscence accompanied by substantial hemorrhage was managed by ligation and hemostasis during a second immobilization. Medical management with nonsteroidal anti-inflammatory drugs and diuretics reduced the mucosal edema and prevented recurrence of the prolapse. A combination of butorphanol and detomidine provided excellent reversible chemical restraint for this animal.

Adenoviral infection in captive moose (Alces alces) in Canada.

Adenoviral infection was associated with hemorrhagic enteritis, serosal hemorrhages, and severe pulmonary edema in six captive moose (Alces alces) in Toronto, Ontario, Canada: an adult female moose and three calves in 1985 and two calves in 1998. Adenoviral disease was suspected based on histological findings of systemic vasculitis and widespread thrombosis associated with amphophilic intranuclear inclusions in endothelial cells. Diagnosis was confirmed by immunohistochemistry using antiserum to bovine adenovirus type 5, transmission electron microscopic identification of viral particles consistent in morphology with adenovirus within nuclei of pulmonary endothelial cells in an affected calf, and virus isolation. The restriction pattern of virus isolated from the lung of one of the calves indicated that the virus was identical to a recently characterized adenovirus in black-tailed deer (Odocoileus hemionus) in California. The moose adenovirus reported here may have been endemic in the captive moose herd, or infection may have resulted from either direct or indirect contact with other species of captive or wild cervids. This is the first report of adenoviral infection in moose and of the presence of adenoviral disease in a cervid in Canada.

Characterization of the hepcidin gene in eight species of bats.

Hemochromatosis, or iron storage disease, has been associated with significant liver disease and mortality in captive Egyptian fruit bats (Rousettus aegyptiacus). The physiologic basis for this susceptibility has not been established. In humans, a deficiency or resistance to the iron regulatory hormone, hepcidin has been implicated in the development of hereditary hemochromatosis. In the present study, we compared the coding sequence of the hepcidin gene in eight species of bats representing three distinct taxonomic families with diverse life histories and dietary preferences. Bat hepcidin mRNA encoded a 23 amino acid signal peptide, a 34 or 35 amino acid pro-region, and a 25 amino acid mature peptide, similar to other mammalian species. Differences in the sequence of the portion of the hepcidin gene that encodes the mature peptide that might account for the increased susceptibility of the Egyptian fruit bat to iron storage disease were not identified. Variability in gene sequence corresponded to the taxonomic relationship amongst species.

Pathologic and hematologic responses to surgically implanted transmitters in eastern massasauga rattlesnakes (Sistrurus catenatus catenatus).

The study of secretive snakes, such as rattlesnakes, has benefited from the use of radiotelemetry. However, the principal assumption in telemetry studies is that the transmitter has no significant effect on the study animal. To test the validity of this assumption, the physiologic and pathologic effects of intracoelomic implants were examined in a group of 24 eastern massasauga rattlesnakes (Sistrurus catenatus catenatus) in a laboratory setting over a period of 58 wk between March 2005 and April 2006. Inflammation and infection were evaluated using gross examination, histopathology, bacteriology, hematology, and plasma protein electrophoresis. Inflammation and infection occurred despite careful surgical procedures and advanced veterinary care. Four of 12 (33%) snakes developed extensive inflammatory response to the transmitter and associated anaerobic and gram-negative bacterial infections. Another four (33%) snakes showed mild inflammatory responses without infection. Reaction to the transmitters was reflected in changes in values for heterophils, monocytes, alpha-1, and beta globulin levels. Some conclusions reached in field studies using implanted radiotransmitters in snakes may be invalid if the implant influences the behavior or survival of the subject. Advances in attachment methods and transmitter coating technology may prevent some of the adverse effects associated with surgically implanted transmitters.

West Nile virus encephalitis in a Barbary macaque (Macaca sylvanus).

An aged Barbary ape (Macaca sylvanus) at the Toronto Zoo became infected with naturally acquired West Nile virus encephalitis that caused neurologic signs, which, associated with other medical problems, led to euthanasia. The diagnosis was based on immunohistochemical assay of brain lesions, reverse transcriptase-polymerase chain reaction, and virus isolation.